Wayne Swan has accused the government of launching ''intergenerational warfare'' against under 35s in the budget and savaging pensioners and low income earners, citing new analysis prepared for the former treasurer.

As Prime Minister Tony Abbott rallied Coalition MPs before his 12-day trip to Indonesia, France, Canada and the US, Mr Swan stepped back into the political arena on Tuesday night as he accused the government of selectively using IMF data to trash his economic record as treasurer.

Mr Swan said the government had attempted to perpetrate three tricks on Australians about the economy - that the nation faced an economic crisis, that spending was massively out of control and that debt levels are ''large, unsustainable and rapidly deteriorating''.

The analysis by the parliamentary library found that the government's claim that Australia had the highest increases in forecast real expenditure growth between 2012 and 2018 for IMF advanced countries was not true.

Mr Swan said the government had ''misused IMF data on spending, deficit and debt to justify their savage cuts by brazenly using the respectability and credibility that body brings to the public debate''.

The purpose of this ''trickery'' was ideological, he added, and helped the government to ''wriggle out of their clear commitments - no cuts to education, no cuts to health, no change to pensions, no change to GST and no cuts to ABC or SBS''.

The outcry over the budget's hit on low income earners and pensioners had masked ''the intergenerational warfare'' that would result in ''cuts to Newstart for under 30s, the deregulation of university fees and higher HECS debts for university students''.

Mr Swan also asserted in the speech that Australia's return to surplus timetable was slightly better than the average of other IMF advanced economies.

In the Coalition party room meeting, two Queensland MPs flagged with Mr Abbott that the decision to abolish a seniors supplements of about $800 annually for Gold Card holders,had caused "blowback" in their electorates and that it would be a hard sell.

Mr Abbott said he understood their concerns but said the policy was necessary. He told MPs his government faced "testing times" after the budget but urged them to be "indefatigable, relentless, decent, sympathetic, compassionate but unapologetic".

Opposition Leader Bill Shorten was lobbied by WA frontbencher Alannah MacTiernan to reach out to aspirational voters in WA and suggested the party rethink its support for the present mining tax, which is almost certain to be abolished when the new Senate sits.

Mr Shorten said the party had discussed dumping the tax before the half-Senate election in April but that it would now be deferred to the national policy making forums.

In question time, Mr Abbott stepped up his defence of the federal budget as he blamed Labor for six years of deficits.

''We were elected to fix the problem, and fix it we will,'' he said.

''That is why this budget reduces projected maximum debt by almost $300 billion.

''We will take the projected deficit in 2017-18 from about $30 billion to under $3 billion within sight of surplus.''

Mr Hockey dismissed Mr Swan's critique of the budget as misleading but relied on the same IMF graphs that the parliamentary library analysis had called into question.

"I have compared Australia to other IMF profiled advanced economies, as is clear and evident in the IMF Article IV Assessment, February 2014,'' he said.

"Mr Swan got the numbers wrong in government and he continues to get them wrong in opposition."